By Jan Wolfe WASHINGTON (Reuters) – A Texas man who joined the Jan. 6, 2021, assault on the U.S. Capitol by former President Donald Trump supporters was found guilty for his role in the attack on Tuesday, a milestone victory for federal prosecutors in the first such case to go before a jury. The defendant, Guy Reffitt, was found guilty on all five of the felony charges he faced, including bringing a gun onto the Capitol grounds and obstructing an official proceeding. Reffitt’s trial was seen as an important test case as the U.S. Justice Department attempts to secure convictions from the hundre…